Automatic feed block molding press for granular materials

ABSTRACT

Electrode blocks are compressed in a vertical mold open above and below by close-fitting upper and lower compression members, the mold and the upper compression member being vertically movable by piston drives. A charging container is laterally movable by a horizontal piston drive from a position on a bracket at one side of the press, in which it receives the granular material to be compressed from a dosage device, dropped in from above. The lateral drive pushes the charging container into the center of the press when the press is open to receive it, so that it can discharge its contents into the mold, after which the container is withdrawn with the help of piston driven flaps opening one side of the container so that it may be removed while the upper compression member is approaching its working position. A piston driven guide sleeve is provided to cover the gap between the dosage device and the charging container when the charge of granular material is dumped from the former to the latter, which occurs during the working stroke of the driven compression member which causes the mold and the support bracket for the charging container to be moved downward.

United States Patent 1191 1111 3,887,685 Stelzmuller June 3, 1975 [54} AUTOMATIC FEED BLOCK MOLDING 3,555,621 1/1971 Hara 425/78 X PRESS FOR GRANULAR MATERIALS 3,764,244 10/1973 Hurley et al. 425/353 X 3,788,787 l/l974 Silbereisen et al 425/260 X [75] Inventor: Franz Stelzmuller, Oensingen,

Swltzerland Primary Examiner-J. Howard Flint, Jr. [73] Assignee: Von Roll A.G., Gerlafingen, Attorney, Agent FirmFlynn & Frishauf Switzerland 22 Filed: July 31, 1973 E d bl k ABSTRACTd 1 1d ectro e 00 s are compresse in a vertlca mo [21] open above and below by close-fitting upper and lower compression members, the mold and the upper [30] Foreign Application Priority Data compression member being vertically movable by pis- Aug. 3, 1972 Switzerland 11488/72 drives- A charging Container is laterally movable by a horizontal piston drive from a position on a {J's- CL n bracket at one Of the press, in it receives 51 Int. Cl B30b 11/02; B30b 15/30 the granular meteelel be eempreseed feel desege [58] Field 61 Search 425/256, 258, 260, 352, devlee, dropped from, above The lateral delve 425/353 354 355, 78 406 44 412 415, pushes the charging contalner into the center of the DIG 115 press when the press is open to receive it, so that it can discharge its contents into the mold, after which [56] References Cited she cortlltainer is withdrawn! wihhthe help of pisilon rlven a s opening one s1 e o t e contalner so t at UNITED STATES PATENTS it may be zemoved while the upper compression meml,967,608 7/1934 Clingan et a] 425/260 her is approaching its working position A piston driven guide sleeve is provided to cover the gap be- 288873l 6/1959 y 'g' /258 X tween the dosage device and the charging container 2 925 619 2/1960 Sindebar ".21: 425/73 when the charge granular mfiteral dumped fmm 3:029:752 M1962 Frank H 425/DIG 115 the former to the latter, whlch occurs during the 3,132,379 5/1964 Crane 425/415 X Working Stroke of the driven Compression member 3,209,057 9/1965 Lassman 425/415 X which causes the mold and the support bracket for the 3,222,748 12/1965 Lamb 425/256 X charging container to be moved downward. 3,266,096 8/1966 Thomas et al. 425/256 X 3,309,750 3/1967 Gally 425/DIG. 115 7 Clams, 5 Drawmg Flgllres AUTOMATIC FEED BLOCK MOLDING PRESS FOR GRANULAR MATERIALS This invention relates to presses for compressing granular material mixed with a binder into solid blocks, especially electrode blocks. More particularly the invention concerns a press using a mold open above and below, operating together with upper and lower compression or stamping members. ln this type of press the mold and one or both compression members are movably mounted in the press frame.

In various industries, particularly in aluminum refining, it is known to use presses to produce blocks of material to serve as anode blocks for electric refining ovens.

The capacity of the known types of presses is limited, because the individual operations, particularly the measuring out of the material, the charging of the mold and the pressing of the material into a block follow in succession. In order to increase capacity, therefore, a number of presses are used. It is also known to break down the operations into stages accomplished with different equipment in which case, for example, precompression is performed in one equipment and final compression in another. The expense of such operations is, however, relatively large and for that reason they are economical only in particularly exacting applications. It is an object of the invention to provide a press for compressing granular material into blocks which is capable of providing a substantial increase of capacity. It is desirable to use a time of compression that is as long as possible, since that reduces the drive power that is necessary. A relatively long compression period is also desirable from a process engineering standpoint, because plastic deformation of the material under compression can then proceed more effectively and uniform density of the block can be obtained.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, a laterally movable charging container is provided that has an openable wall provided with a piston drive by which that wall can be held closed and by which it can be brought into open position. In this manner the pressing operation can already begin before the charging container has been removed from the compression site and, nevertheless, the next charging operation can be prepared during pressing of a block.

The charging container is open above and below and its bottom slides over a surface flush with the top end of the mold, so that at the outer end of its lateral movement, where it is resting on a bracket attached to the mold, it is loaded by material dumped into it from above by a dosage device and guided by a sleeve that encloses the loading path. The sleeve is extended into position before loading in order to allow for downward movement of the charging container and its support bracket resulting from reaction of the mold to the power stroke of the movable plunger of the press. At

the other end of its travel the charging container moves .per is provided on the exterior of the charging container for that operation.

The movements of the mold, the movable compression member or members, the charging container and its movable wall, as well as the discharge of the dosage device and the extension of the guide conduit sleeve are preferably all driven and synchronized by hydraulic piston drives.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGS. 1 to 4, inclusive, are vertical sections, partly in elevation, of a diagrammatically represented press in accordance with the invention, respectively showing the press at various stages of operation in a single operation cycle; and

FIG. is a top view of the charging container of a press according to the invention provided with an openable wall actuated by means of piston drives.

In FIGS. 1 to 4, inclusive, a movable mold 2, a fixed lower compression member or anvil 3 and an upper movable compression member or ram 4 are mounted on a diagrammatically represented press frame 1. The compression member 4 is a part of a press piston 6 protruding into a press cylinder 5. The pressure medium (which may be hydraulic) can enter or leave the cylinder 5 through a passage 7. On both sides of the press cylinder 5 are rapid motion cylinders 8 for providing the necessary quick return motion. The pistons of these rapid motion cylinders are provided with piston rods 9 affixed to a cross piece 10 mounted on the movable compression member 4. The rapid motion piston drives 8,9 are reversible, whereas the main cylinder 5 and the press piston 6 provide a single acting or one-way piston drive.

Another pair of piston drives 14 is provided at the base of the press frame 1. These drives move the mold 2. A bracket 15 is affixed to the mold 2 for support of the charging container 16 that is arranged to slide horizontally on the upper surface of the bracket and the mold, as driven by a piston drive 17. At one end of its travel the charging container 16 is in the middle of the press, whereas at the other end of its travel it is located under a dosage device collectively designated 18 that measures out the filling material. The granular material is supplied over a conveyor belt 19 and a conveyor chute 20 which may, for example, be an oscillating chute, by which it is delivered to a weighing container 21. Here the charge for the next compression step is prepared and weighed by means of a scale 22. Piston drives 23 are provided on the weighing container 21 for raising and lowering a guide conduit. The guide conduit 24, in the form of a vertical sleeve, serves to provide a closed connection from the weighing container to the charging container 16, so that when the trap door that forms the floor of the weighing container 21 is opened the entire charge of material is dumped into the charging container without loss.

It is important that the charging container 16 has one wall 25 that can be moved out of the way by means of piston drives 27 as described with reference to FIG. 5.

In FIG. 5 the charging container 16 is represented as seen from above. The piston drive 17 acts by means of a plate 28 fixed on the charging container 16. The latter is slidably mounted by means of guide bushings 30 on guide rods 29. The wall 25 of the charging container consists of two flaps, or door leaves, mounted to swing on hinges 31. Each of the two piston drives 27 grips a lever 32 connected with one of the flaps of the wall 25.

By actuation of the piston drives 27, the flaps of the wall 25 are swung in the direction of the two arrows until they reach the position shown in broken lines, at which point this side of the charging container is fully open. On the outside of the flaps of the wall 25 are respectively located two bumpers 33 by means of which a block completely pressed in the previous operation can be pushed on to a roller conveyor 35 adjacent to the press, when the charging container 16 is moved into the press.

An operating cycle of the press just described proceeds as follows:

In FIG. 1 the press is in its normal or idle position, i.e. the mold 2 is fully depressed and the end plate 36 of the lower compression member 3 is flush with the end surface of the mold 2 and with the support surface surface of the bracket 15. The movable upper compression member 4 is in its highest position. The charging con tainer 16 is filled with a charge of material to be compressed. The flaps of the openable wall 25 of the charging container 16 are closed and the bumpers 33 are in position for knocking the completed block 37 out of the press. The bottom (not shown) of the weighing container 21 is closed and the scale 22 is measuring the weight of the material flowing over the chute 20 as it pours in. The completed block 37 pressed in a previous cycle of operation stands ready to be knocked on to the roller chute 35.

The filled charging container 16 now begins to travel into the space between the two compression members 3 and 4, and at the same time oil nozzles 38 provided in the charging container spray a lubrication oil mist on the faces of the respective compression plates 12 and 36 in order to prevent adhering of the block to the same. The bumpers 33 push the block 37 until the charging container 16 has reached the middle of the press.

The mold 2 is now raised, raising with it the bracket and the charging container 16, so that the charging container can now empty itself into the space enclosed by the mold 2 above the lower compression member 3. As the mold is raised an oil mist is sprayed on to the inner walls of the mold from a number of nozzles 40 provided in the lower compression member 3.

In FIG. 2 the mold 2 is raised to its upper extreme position and the contents of the charging container 16 have been completely dropped into the mold 2. The walls of the charging container 16 enclose the upper compression member 4.

The pressing operation now begins, first with precompression of the charge produced by the rapid mo tion piston drives 8,9 of the upper compression member 4. At the same time the flaps of the openable wall 25 of the charging container 16 are opened, so that the container can be moved laterally out of the press. As soon as the charging container 16 gets back to the other end of its travel underneath the weighing container 21, at the left in FIGS. 1-4, the flap wall 25 closes and the guide conduit 24 is then lowered over the charging container, as shown in FIG. 3.

FIG. 3 shows the position of the press at the beginning of the main compression operation, during which the mold 2 is knocked downward against a counter force brought to bear by means of the piston drives 14 causing the mold to hover in an intermediate position. The mold is driven downward only far enough to place the completely compressed block in about the middle of the mold 2. Before the termination of the compression operation, which occurs with pressure applied to main cylinder 6, the mold is held between opposing forces and upon the drive pressure exceeding a certain specific compression on the block being formed, it is dragged along downwards a little way.

When the pressing operation is terminated, the weighing container 21 at the same time becomes filled with a new dosage quantity of material for compression, at which point the conveyor chute 20 is momentarily held still in nondelivering position, as shown in FIG. 3. The trap bottom (not visible in the drawing) of the weighing container 21 opens and allows the filling material to be dumped into the charging container 16.

The weighing container 21 is then closed again and the inflow of granular material from the conveyor belt 19 sets the conveyor chute 20 back into operation. while the upper compression member 4 begins to move towards its upper terminal position under its quick return drive, as shown in FIG. 4. At the same time the mold 2 is lowered, which causes the block 37' that rests on the lower compression member 3 to be stripped from the descending mold 2. When the mold 2 reaches its bottom position, the press is returned to its normal or idle position shown in FIG. 1 and the operation cycle can begin again.

The guide conduit sleeve 24 is necessary to avoid risk of loss of the input material, because during the stage shown in FIG. 2 the mold 2 is held hovering between opposing forces and can also be dragged along somewhat by the downward push of the close-fitting upper compression member 4. That downward movement of the mold which is not necessarily always of the same extent, is communicated to the bracket 15 and the charging container 16, but the presence of the guide conduit 24 lowered over the top of the charging container l6 prevents that downward movement from opening up a gap through which any of the material dumped from the weighing container 21 into the charging container 16 might escape.

Although the invention has been described with respect to a particular illustrative embodiment, it is to be understood that variations and modifications are possible within the inventive concept here set forth.

I claim:

1. A block molding press particularly suited for forming block electrodes by compression of granulated material mixed with a binder comprising, in combination with a press frame:

mold means open above and below;

an upper and a lower compression means fitting into said mold means respectively from above and below;

actuating means for moving said mold means and at least one of said compression means vertically with respect to said press frame;

a dosage device (18) for said granular material;

a laterally movable charging container (16) movable between a position below the discharge of said dosage device and a position above the upper opening of said mold means (2) and having an openable wall (25), said charging container means (16) also being'open above and below and being slidably supported on a surface flush with the top of said mold means (2) provided by bracket means (15) affixed to said mold means (2);

lateral drive means (17) for laterally moving said charging container (16) for charging said mold means (2) and expelling a previously pressed block in synchronism with operation of said actuating means; and operating means (27) connected to said openable wall (25) for opening and closing said wall and for maintaining said wall in open or closed position as required in synchronism with the operation of said actuating means and said lateral drive means,

said actuating means and said lateral drive means being so synchronized that one of said compression means protrudes at least part way into said charging container (16) before said charging container is moved away from its said position above the upper opening of said mold means.

2. A press as defined in claim 1, in which said dosage device (18) includes a weighing container (21) disposed above the loading position of said charging container l6) and in which there is provided between said weighing container and said charging container a vertically movable guide conduit (24) and in which vertical drive means (23) are provided to displace said guide conduit (24) so as to enclose a path between said weighing container (21) and said charging container (16) when the latter is in its loading position, regardless of any vertical lowering of the position of said charging container (16) as the result of displacement of said mold means (2) by a concurrent pressing operation.

3. A press as defined in claim 1, in which bumper means (33) are provided on the outside of said charging container (16).

4. A press as defined in claim 1, in which said charging container is provided with means (38) for spraying oil on the faces of said compression means.

5. A press as defined in claim 1, in which said lower compression means is provided with means (40) for projecting oil particles into the interior of said mold means (2).

6. A block molding press as defined in claim 1 in which said upper compression means is movable by said actuating means and in which said actuating means are arranged to insert said upper compression means partly into said charging container (16) when said charging container is in its position above the upper opening of said mold means, and in which, further, said operating means are arranged to open said wall (25) to permit said lateral drive means (17) to move said charging container (16) away from said position above the upper opening of said mold means.

7. A block molding press as defined in claim 6 in which said lower compression means is fixed, in which said lateral drive means (17) are mounted on said bracket means (15) so as to be vertically moved with said mold means, and in which said actuating means are arranged to raise said mold means during the filling of said mold means from said charging container. 

1. A block molding press particularly suited for forming block electrodes by compression of granulated material mixed with a binder comprising, in combination with a press frame: mold means open above and below; an upper and a lower compression means fitting into said mold means respectively from above and below; actuating means for moving said mold means and at least one of said compression means vertically with respect to said press frame; a dosage device (18) for said granular material; a laterally movable charging container (16) movable between a position below the discharge of said dosage device and a position above the upper opening of said mold means (2) and having an openable wall (25), said charging container means (16) also being open above and below and being slidably supported on a surface flush with the top of said mold means (2) provided by bracket means (15) affixed to said mold means (2); lateral drive means (17) for laterally moving said charging container (16) for charging said mold means (2) and expelling a previously pressed block in synchronism with operation of said actuating means; and operating means (27) connected to said openable wall (25) for opening and closing said wall and for maintaining said wall in open or closed position as required in synchronism with the operation of said actuating means and said lateral drive means, said actuating means and said lateral dRive means being so synchronized that one of said compression means protrudes at least part way into said charging container (16) before said charging container is moved away from its said position above the upper opening of said mold means.
 1. A block molding press particularly suited for forming block electrodes by compression of granulated material mixed with a binder comprising, in combination with a press frame: mold means open above and below; an upper and a lower compression means fitting into said mold means respectively from above and below; actuating means for moving said mold means and at least one of said compression means vertically with respect to said press frame; a dosage device (18) for said granular material; a laterally movable charging container (16) movable between a position below the discharge of said dosage device and a position above the upper opening of said mold means (2) and having an openable wall (25), said charging container means (16) also being open above and below and being slidably supported on a surface flush with the top of said mold means (2) provided by bracket means (15) affixed to said mold means (2); lateral drive means (17) for laterally moving said charging container (16) for charging said mold means (2) and expelling a previously pressed block in synchronism with operation of said actuating means; and operating means (27) connected to said openable wall (25) for opening and closing said wall and for maintaining said wall in open or closed position as required in synchronism with the operation of said actuating means and said lateral drive means, said actuating means and said lateral dRive means being so synchronized that one of said compression means protrudes at least part way into said charging container (16) before said charging container is moved away from its said position above the upper opening of said mold means.
 2. A press as defined in claim 1, in which said dosage device (18) includes a weighing container (21) disposed above the loading position of said charging container (16) and in which there is provided between said weighing container and said charging container a vertically movable guide conduit (24) and in which vertical drive means (23) are provided to displace said guide conduit (24) so as to enclose a path between said weighing container (21) and said charging container (16) when the latter is in its loading position, regardless of any vertical lowering of the position of said charging container (16) as the result of displacement of said mold means (2) by a concurrent pressing operation.
 3. A press as defined in claim 1, in which bumper means (33) are provided on the outside of said charging container (16).
 4. A press as defined in claim 1, in which said charging container is provided with means (38) for spraying oil on the faces of said compression means.
 5. A press as defined in claim 1, in which said lower compression means is provided with means (40) for projecting oil particles into the interior of said mold means (2).
 6. A block molding press as defined in claim 1 in which said upper compression means is movable by said actuating means and in which said actuating means are arranged to insert said upper compression means partly into said charging container (16) when said charging container is in its position above the upper opening of said mold means, and in which, further, said operating means are arranged to open said wall (25) to permit said lateral drive means (17) to move said charging container (16) away from said position above the upper opening of said mold means. 